20725684625 has 16 divisors (see below), whose sum is σ = 25953978960. Its totient is φ = 16523929600.

The previous prime is 20725684619. The next prime is 20725684667. The reversal of 20725684625 is 52648652702.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 2307937681 + 18417746944 = 48041^2 + 135712^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20725684625 is a prime.

It is a super-2 number, since 2×20725684625² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20725684625.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 246320 + ... + 319569.

It is an arithmetic number, because the mean of its divisors is an integer number (1622123685).

Almost surely, 2^20725684625 is an apocalyptic number.

20725684625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20725684625 is a deficient number, since it is larger than the sum of its proper divisors (5228294335).

20725684625 is an equidigital number, since it uses as much as digits as its factorization.

20725684625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 566197 (or 566187 counting only the distinct ones).

The product of its (nonzero) digits is 1612800, while the sum is 47.

The spelling of 20725684625 in words is "twenty billion, seven hundred twenty-five million, six hundred eighty-four thousand, six hundred twenty-five".